Liomopterella pediaecetae, new species from the Oklahoma Wellington Formation, is described as the first North American representative of the genus Liomopterella Sharov, 1961. The previously described species of Liomopterella have been from Russian Permian localities, so the new species significantly extends the biogeographical range of the genus; it also becomes the third species of Liomopteridae known from Oklahoma, the seventh species from the Wellington Formation, and the tenth from North America.